A Ford Mustang station wagon? Maybe not such a good idea. But someone thought so in 1966. / Ford

by Chris Woodyard, USA TODAY

by Chris Woodyard, USA TODAY

With a new Mustang on the way timed to the 50th anniversary of the 1964 model that started it all, Ford has dug into its archives to show off the models that never quite made the grade.

Some are sublime, some downright cool -- and others, like the four-door Mustang concept, are hideous. Taken as a whole, they show how Ford has been willing to take risks over the years on its original pony car. Some, like the original, worked. Others, like the Mustang II of the 1970s, should have been hauled off to the glue factory.

The all-new 2015 Ford Mustang is expected to take styling in a new direction, away from the last two generations that have largely aped the look of the best, early years of the model. It's yet to be seen whether purists are willing to accept the change, or will defect in droves.